plot.py function get_ugf to return the index, magnitude, and phase where it found the UGF

get_ugf in the plot.py class is really nice. I'm a little confused about the interpolation that needs doing, but setting that aside for a moment, I'd love it if the function returned the index of the frequencies vector that it found the UGF, as well as the magnitude and phase of the darm_olg_tf where it found the UGF.

Note, if this frequency, index, and transfer function value is somehow different than what can be used with the input frequencies vector, I wanna know that and have the values for all of it -- the new interpolation frequency vector, the tf value, and then the nearest value (and index of) on the frequencies vector that match the interpolated value.

Why?

• When plotting the darm_olg_tf, I want to highlight where the unity gain frequency is by putting marker there in both magnitude and phase.
• When computing the residual time delay between A and C, I want to make a plot showing where the A and C functions cross over, i.e. the darm_olg_tf UGF.